This invention relates to a vehicle seat. More particularly, the present invention relates to a vehicle seat suitable for a welfare vehicle in which an elderly person, a physically handicapped person or other such persons (hereinafter simply referred to as “occupant”) is capable of easy getting in and out of a vehicle.
A vehicle seat is taught by, for example, Japanese Laid-Open Patent Publication No. 2005-14672. This vehicle seat includes a seat main body having a seatbelt, a first sliding mechanism that is capable of slide the seat main body in forward and rearward directions of a vehicle with respect to a vehicle floor, and a rotation mechanism that is capable of horizontally rotating the seat main body through an angle of 90 degrees between a forwardly facing position where it faces a front side of a vehicle and a laterally facing position where it faces a door opening of the vehicle.
This vehicle seat further includes a vertically moving mechanism that is positioned between the seat main body and the rotation mechanism. The vertically moving mechanism includes a second sliding mechanism and a pair of four-bar linkage mechanisms, so as to vertically and laterally move the seat main body between vehicle interior and vehicle exterior via a door opening while the seat main body is in the laterally facing position.
In addition, this vehicle seat includes a third sliding mechanism that is positioned between the seat main body and the vertically moving mechanism, so as to laterally slide the seat main body independently of the second sliding mechanism of the vertically moving mechanism.
According to the vehicle seat thus constructed, the seat main body can be moved between vehicle interior and vehicle exterior via the door opening while the seat main body is rotated to the laterally facing position. As a result, an occupant can easily get in and out of the vehicle.
Further, the vehicle seat includes a fixture mechanism (an force transmitting mechanism) in order to effectively anchor or affix the vehicle seat (the seat main body) to the vehicle floor when a large (inertial) force (which force may be referred to as a seatbelt loading) is unexpectedly applied to the seat main body via the occupant sitting on the seat main body. Such a large seatbelt loading can be produced, for example, when a vehicle collision, in particular, a front-side collision happens. The fixture mechanism is composed of a first fixture unit positioned between the seat main body and the vertically moving mechanism and a second fixture unit positioned between the vertically moving mechanism and the vehicle floor. The first and second fixture units are arranged and constructed to engage each other when the large force is applied to the seat main body, so as to affix the vehicle seat (the seat main body) to the vehicle floor.
Therefore, according to the vehicle seat thus constructed, the vehicle seat (the seat main body) can be rigidly integrated with the vehicle floor even if the large force is applied to the seat main body. That is, the vehicle seat (the seat main body) cannot be moved on the vehicle floor even if the large force is applied to the seat main body. As a result, the occupant sitting on the seat main body can be reliably restrained with respect to the vehicle floor.
Generally, the vehicle seat (the seat main body) is designed such that a child seat (a safety seat) can be attached thereto. That is, as shown in FIGS. 12 and 13, the seat main body (which is shown by a reference numeral 250) includes a cushion frame 210. The cushion frame 210 is composed of a pair of (left and right) longitudinal side frame elements 204 and an anchor frame 205. The anchor frame 205 is positioned between rear ends of the side frame elements 204 and is connected thereto at both ends thereof. The anchor frame 205 is provided with a pair of anchor members (child seat attachment members) 206 that are positioned spaced away from each other. The vehicle seat (the seat main body 250) further includes a support frame (a seat support) 200. The support frame 200 is composed of a pair of (left and right) longitudinal frame elements 201 positioned in parallel with each other and a pair of (front and rear) lateral frame elements 202 and 203 positioned in parallel with each other. Both ends of each of the frame elements 202 and 203 are respectively connected to the side frame elements 204 of the cushion frame 210 so that the cushion frame 210 can be integrated with the support frame 200.
According to the vehicle seat thus designed, the child seat can be attached to the seat main body 250 utilizing the anchor members 206. However, for example, when the vehicle collision happens, a large (inertial) force (which force will be hereinafter referred to as a safety seat loading) can be applied to the child seat. When the large force is applied to the child seat, as shown by dot-line arrows P in FIG. 13, the force can be transmitted to the rear lateral frame element 203 of the support frame 200 via the anchor members 206, the anchor frame 205 and the side frame elements 204. The force thus transmitted can be converted to upward moments as shown by outline arrows M in FIG. 13. The upward moments thus produced are respectively applied to both ends of the rear lateral frame element 203, so that the rear lateral frame element 203 can be deformed or damaged. Upon deformation or damaging of the rear lateral frame element 203, the cushion frame 210 can be displaced with respect to the support frame 200. As a result, the seat main body 250 can be moved in the vehicle seat. That is, the seat main body 250 can be moved with respect to the vehicle floor. Thus, the child seat attached to the seat main body 250 cannot be reliably restrained or immobilized with respect to the vehicle floor. This means that an occupant (baby or infant) sitting on the child seat cannot be reliably restrained or immobilized with respect to the vehicle floor.
Therefore, the known vehicle seat 1 till is in need of improvement. Thus, there is a need in the art for an improved vehicle seat.